1. Field of the Invention
The invention relates to a window blind, more particularly to a cordless window blind.
2. Description of the Related Art
As shown in FIGS. 1 and 2, a conventional cordless window blind 1 is disclosed to include a stationary seat 11 fixedly mounted over a top of a window, a blind mechanism 12 connected releasably to the stationary seat 11, a control pole 10, a coupling mechanism 13 connected to the control pole 10 and the blind mechanism 12, and an anti-rotation seat 14 fixedly mounted on a wall surface below the window and formed with an engaging groove 141.
The blind mechanism 12 includes a blind member 121 having one end that is connected to the stationary seat 11, a linking rod 122 mounted rotatably to the stationary seat 11, a sheet member 123 having one end that is connected to the linking rod 122 and wound releasably thereon, and a plurality of spaced-apart connecting members 124 interconnecting the blind member 121 and the sheet member 123. The coupling mechanism 13 includes a first gear 131 connected co-rotatably to the control pole 10, and a second gear 132 connected co-rotatably to the linking rod 122 and meshing with the first gear 131. The control pole 10 has an anti-rotation segment 101 that is engageable with the anti-rotation seat 14 for preventing the control pole 10 from rotating.
When the control pole 10 is rotated, the linking rod 122 rotates via transmission between the first gear 131 and the second gear 132 of the coupling mechanism 13 and can retract the sheet member 123 and the blind member 121. When the blind member 121 is moved to a desired position, the anti-rotation segment 101 of the control pole 10 is engaged to the engaging groove 141 of the anti-rotation seat 14 for stopping the rotation of the control pole 10 and retaining the desired position of the blind member 121. If the blind member 121 needs to be released afterward, the anti-rotation segment 101 of the control pole 10 is disengaged from the engaging groove 141 of the anti-rotation seat 14 so as to permit the rotation of the control pole 10, and the blind member 121 would be automatically released due to the weight thereof.
However, the engagement and disengagement between the control pole 10 and the anti-rotation seat 14 have to be performed by a user close to the wall surface, thereby causing inconvenience to the user. Besides, due to the weight of the blind mechanism 12, at the moment of disengaging the control pole 10 from the anti-rotation seat 14, the sheet member 123 and the blind member 121 may suddenly be released, thereby causing difficulty for positioning the blind member 121 of the blind mechanism 12 before the release or retraction of the blind member 121.